ECONOMIC IMPLICATIONS OF ANTIMICROBIAL RESISTANCE

6. ECONOMIC IMPLICATIONS OF ANTIMICROBIAL RESISTANCE

Antimicrobial resistance is not only a medical problem but also an eco- nomic one (Paladino et al., 2002). Resistant organisms cause infections that are more difficult to treat, requiring drugs that are often less readily available, more expensive, and more toxic (Carmeli et al., 1999; Howard et al., 2001). In some cases, certain strains of microbes have become resistant to all available antimicrobial agents (Russo and Johnson, 2003). Resistant Gram-negative and Gram-positive bacteria have been associated with increased direct medical costs ranging from several thousand dollars to tens of thousands of dollars per patient (Paladino et al., 2002). With increasing frequency and levels of AR, drug therapy must be viewed in an economic sense. Several factors impact on cost-effective antimicrobial therapy, including drug cost, drug efficacy and

632 Denis K. Byarugaba duration of treatment, dose regimen, diagnostic strategies, microbial resistance,

and patient compliance. Comparison has been made of the impacts of infections due to antimicrobial- resistant bacteria with those of infections due to antimicrobial-susceptible strains of the same bacteria. Data shows that for both nosocomial and community- acquired infections, the mortality, the likelihood of hospitalisation and the length of hospital stay were usually at least twice as great for patients infected with drug-resistant strains as for those infected with drug-susceptible strains of the same bacteria (Holmberg et al., 1987). Tuberculosis, treatment costs have been estimated at US$20 for regular treatment, while the cost of treating MDR-TB rises to US$2,000 (WHO, 2001). For HIV/AIDS, it has been indi- cated that resistance to one protease inhibitor results in resistance to the entire family of drugs thus implying higher costs of treatment of the insensitive strains. This applies to all other major killers such as ARIs, diarrhoeal dis- eases, malaria, and other STDs which are very prevalent in DCs. Poor out- comes could be attributed both to the expected effects of ineffective antimicrobial therapy and to the unexpected occurrence of drug-resistant infections complicated by prior antimicrobial therapy for other medical prob- lems. Although the adverse economic and health effects of drug-resistant bac- terial infections can only be roughly quantified, AR is an important health problem and an economic burden to society (Cosgrove and Carmeli, 2003).

Unfortunately the costs for production of new drugs and introduction onto the market are enormous, estimated at a minimum of US$300 million. This partly explains the reason why since 1970, there have been few classes of antimicrobial agents developed. Their development also takes a period of 10–20 years. Although DCs have the enormous potential of hotspot virgin tropical forests that harbour a lot of plant resources that may provide solutions to many of the current resistance problems, their exploitation requires similar huge financial resources and time to develop them to market level.

Besides the direct costs, there are also biological costs associated with development of AR (Gillespie and McHugh, 1997; Nyamogoba and Obala, 2002) and more importantly, costs related to loss of life and hours spent with- out productive work during long hospitalisation with resistant disease agents. Table 8 shows the extent of the deaths resulting from major killer diseases in the DCs.

Together, HIV/AIDS, tuberculosis, and malaria claimed 5.7 million lives in 2002 and caused debilitating illness in many millions more (Goeman et al., 1991; WHO, 2002). These are the lives of infants, young children, and young mothers and fathers and the economically most important group in their prime productive years. Resistance to these disease agents puts a heavy burden on the already strained public health.

AR and its Containment in DCs 633

Table 8. Occurrence of the major killer diseases in the world and proportion of their occurrence in developing countries

Disease Deaths per year

Percentage in developing (in million)

New cases per year

countries (%) HIV/AIDS

(in million)

3 5.3 92 Tuberculosis

1.9 8.8 84 Malaria

Nearly 100 Source: WHO (2002).